The inner bottom of the vessel forms a void that houses the gasoline fuel tanks and supply-piping to the engines in the engine compartment. The void has no forced ventilation so the operator cannot purge any gasoline fumes from the void before starting the engines. Similarly the engine compartment also has no ventilation fan to remove gases before starting the engines. The operator had run the vessel previously and was used to starting the engines without pre start-up ventilation. Consequently, he followed the same method on the day of the occurrence with catastrophic results. The operator did not check the engines before attempting to start them. This activity would have required him to open the engine compartment to reach the engines and may have led to the discovery of fuel in the bilge. In the two days before the layover in Comox, the vessel had been fishing in rough seas in the Georgia Strait. It is likely that the fuel lines from the tanks in the void space to the engines were shaken enough either to slacken back a union fitting or crack the lines. A further possibility is that the fuel tanks themselves were shaken enough to crack a weld. Either of these two scenarios would have resulted in a build-up of gasoline in the void, the engine compartment or in both spaces. High Water was only seven minutes before the occurrence and the wind was south-easterly. When the Sha 122 was cleared from the dock, the wind was pushing it downwind onto the wooden wharf fitted with the six-inch jet fuel lines. The lack of a floating boom or chain to prevent vessels from approaching the wooden wharf places the six-inch diameter aviation jet A and B fuel lines at risk. A floating boom could be easily laid against the two free-standing piles located to the east of the wooden wharf. The fire generated enough heat for the aluminum of the inner bottom and the engine compartment bulkhead to burn.Analysis The inner bottom of the vessel forms a void that houses the gasoline fuel tanks and supply-piping to the engines in the engine compartment. The void has no forced ventilation so the operator cannot purge any gasoline fumes from the void before starting the engines. Similarly the engine compartment also has no ventilation fan to remove gases before starting the engines. The operator had run the vessel previously and was used to starting the engines without pre start-up ventilation. Consequently, he followed the same method on the day of the occurrence with catastrophic results. The operator did not check the engines before attempting to start them. This activity would have required him to open the engine compartment to reach the engines and may have led to the discovery of fuel in the bilge. In the two days before the layover in Comox, the vessel had been fishing in rough seas in the Georgia Strait. It is likely that the fuel lines from the tanks in the void space to the engines were shaken enough either to slacken back a union fitting or crack the lines. A further possibility is that the fuel tanks themselves were shaken enough to crack a weld. Either of these two scenarios would have resulted in a build-up of gasoline in the void, the engine compartment or in both spaces. High Water was only seven minutes before the occurrence and the wind was south-easterly. When the Sha 122 was cleared from the dock, the wind was pushing it downwind onto the wooden wharf fitted with the six-inch jet fuel lines. The lack of a floating boom or chain to prevent vessels from approaching the wooden wharf places the six-inch diameter aviation jet A and B fuel lines at risk. A floating boom could be easily laid against the two free-standing piles located to the east of the wooden wharf. The fire generated enough heat for the aluminum of the inner bottom and the engine compartment bulkhead to burn. The Sha 122 had no forced ventilation to purge the void space and/or engine compartment before the engines were started. The operator did not inspect the engines or engine compartment before attempting to start the engines. The Sha 122 had been fishing in rough seas before berthing at Comox and the heavy movements may have caused a fuel leak in either the void space or engine compartment. The source of fuel ignition is most likely the starter motor of the port engine. The operator was protected from fire by the canvas that wrapped around him, and by being blown out of the vessel and away from the fire. The piled wooden wharf, running from the shore to the DND fuel wharf, has no protection from vessels either drifting or driven down onto it from the south-east. The exposed jet fuel lines on the east side of the wharf are in danger of being fractured or gashed by vessels at high tides.Findings The Sha 122 had no forced ventilation to purge the void space and/or engine compartment before the engines were started. The operator did not inspect the engines or engine compartment before attempting to start the engines. The Sha 122 had been fishing in rough seas before berthing at Comox and the heavy movements may have caused a fuel leak in either the void space or engine compartment. The source of fuel ignition is most likely the starter motor of the port engine. The operator was protected from fire by the canvas that wrapped around him, and by being blown out of the vessel and away from the fire. The piled wooden wharf, running from the shore to the DND fuel wharf, has no protection from vessels either drifting or driven down onto it from the south-east. The exposed jet fuel lines on the east side of the wharf are in danger of being fractured or gashed by vessels at high tides. The fire was most likely caused by gasoline fuel in the void space or engine compartment that was ignited when the port engine starter was engaged. The lack of forced ventilation in the void space and the engine compartment prevented the operator from properly purging any gasoline vapours from the spaces before starting the engines.Causes and Contributing Factors The fire was most likely caused by gasoline fuel in the void space or engine compartment that was ignited when the port engine starter was engaged. The lack of forced ventilation in the void space and the engine compartment prevented the operator from properly purging any gasoline vapours from the spaces before starting the engines. The harbour master of the Comox Small Craft Harbour requested that a floating boom be installed to prevent any vessel from contacting the wooden wharf. This request was acted upon by Small Craft Harbours and a floating boom now protects the jet fuel lines on the Department of National Defence wharf.Safety Action Taken The harbour master of the Comox Small Craft Harbour requested that a floating boom be installed to prevent any vessel from contacting the wooden wharf. This request was acted upon by Small Craft Harbours and a floating boom now protects the jet fuel lines on the Department of National Defence wharf.